[en] A technique for measurement of the magnetic field topography in the SP-73 electromagnet of the POSITRONIJ facility on the channel of the U-70 accelerator is proposed and described. The magnetic field values were measured by means of the Hall transformer, the magnetic field being regularly checked in reference points with a NMR magnetometer. A step-by-step movement of magnetic field sensors was automatically controlled by the M-6000 computer. Measurement data were recordrd on a magnetic tape with alpha-numeric output at the end of each cycle. Using the above equipment, magnetic fields for three current values applied to the electromagnetic have been measured. A total of 10⁵ measured values of the magnetic field has been obtained